1. Technical Field
The present disclosure relates to a photosensor. The present disclosure also relates to an imaging device.
2. Description of the Related Art
Photodetectors and image sensors include photodetector elements. Typical examples of photodetector elements include photoelectric conversion elements, such as photodiodes and phototransistors. As well known, light can be detected by detecting photocurrent caused by light irradiation in a photoelectric conversion element.
Japanese Unexamined Patent Application Publication No. 2011-60830 discloses in FIG. 2a thin-film transistor (TFT) including an organic film containing a predetermined compound dispersed in an organic polymer as a gate-insulating film. The predetermined compound of the organic film is a compound that changes polarization upon light irradiation. In the thin-film transistor described in Japanese Unexamined Patent Application Publication No. 2011-60830, light irradiation on the gate-insulating film changes the dielectric constant of the gate-insulating film. Thus, light irradiation on the gate-insulating film changes the electric current flowing between the source and the drain. Japanese Unexamined Patent Application Publication No. 2011-60830 discloses that such a thin-film transistor can be used in a photosensor.